CN113498366B

CN113498366B - Apparatus and method for butt welding workpieces

Info

Publication number: CN113498366B
Application number: CN201980080561.8A
Authority: CN
Inventors: M·施托克
Original assignee: Electric Welding Machine Factory Of August Strecker Co ltd
Current assignee: Electric Welding Machine Factory Of August Strecker Co ltd
Priority date: 2018-12-04
Filing date: 2019-12-02
Publication date: 2024-06-25
Anticipated expiration: 2039-12-02
Also published as: DK3826795T3; ES2909732T3; WO2020114980A1; US11919101B2; EP3826795B1; DE102018130769B3; EP3826795A1; CN113498366A; US20210394296A1

Abstract

The invention relates to a butt welding device and a method for butt welding workpieces, in particular wires, strands and profiles, in particular for double-wire-electrode-resistance butt welding, comprising a first clamping tool and a second clamping tool for receiving the ends of the workpieces to be joined. The at least one clamping tool is movable between an initial position and a welding position. At least one deburring tool is provided for deburring the welded end portion of the workpiece. Furthermore, at least one sensor is provided for determining the geometry, in particular the diameter, width or height, of the workpieces to be joined in the joining plane or in a plane substantially parallel thereto, wherein the control device controls the movement of the clamping tool and/or the movement of the deburring tool as a function of the geometry.

Description

Apparatus and method for butt welding workpieces

Technical Field

The present invention relates to an apparatus and method for butt welding workpieces.

Background

Depending on the type, it is known to connect the ends of workpieces, in particular wires, strands or profiles, by means of a corresponding butt welding device. The joining of the workpieces is thus carried out by means of preferably automatic butt welding, so that workpieces of the desired length are produced.

In the known device, for example, the ends of the wires are welded to one another on the end sides. For this purpose, the device generally has two clamping jaws which are movable relative to one another, in which the wire ends are clamped. Subsequently, the clamping jaws with the wire ends are moved towards each other and the welding process is started. Therefore, at the time of welding, the material of the wire end portion is compressed, and burrs are formed at the welding site or the weld joint. These burrs can be removed, for example, by means of a planer type device.

The material to be welded is typically concrete rib steel, however other material qualities can be so joined, such as high carbon steel or alloy steel, as well as non-ferrous materials, such as copper, aluminum or alloys thereof.

Depending on the quality, different annealing options can be implemented, including programmable microprocessor control of the welding process and the annealing process, or of course also an adjustable infrared pyrometer.

Also known are so-called double compression butt welding devices (Doppelstauch-Stumpfschwei beta-Vorrichtung) with automatic deburring. Excellent weld quality is produced by double compression. Almost all of the heated, liquid-forming material is pressed out of the connection. In this way, a very high strength weld is produced. Automatic deburring integrated into the process provides a weld of the same diameter as the original material. In addition, the risk of wire breakage due to excessive deburring is almost eliminated. In other words, an exactly reproducible welded connection of identical diameter, even in the case of difficult-to-machine materials, forms a solid basis for further production processes.

Furthermore, a resistance butt welding machine is known from DE 21 43 917 A1, which welds a rope using ceramic tubes surrounding the rope ends, wherein a holder, which comprises an integral or split ceramic tube immovably during welding, is arranged between clamping devices for the rope ends to be welded.

A method for electrically butt welding a metal conductor in the form of a wire or strand is known from DE 29 34 A1, in which the ends of the metal conductor to be connected are butt welded to the end cross section and the connection points of the butt welded conductors are upset at high temperature. Subsequently, the increased cross section of the compression zone is reduced to an end cross section by cold forming.

DE 28,39,537 A1 also discloses a device for supplying and automatically butt welding wire, wherein a support means and a guide means for advancing the wire, which are provided with a stop, are arranged in pairs. The clamping tool holds the end of the wire and enables a subsequent movement of the wire blocked in the clamping jaw of the device. Furthermore, a tool for throwing out the welded wire is provided.

DE 1 130 541 A1 relates to a method and a device for resistance-combustion butt welding (WIDERSTANDS-Abbrenn-Stumpfschwei βen) of the end face of a strip end and for subsequent processing of the weld seam by progressive feeding of the strip to a stationary processing station.

A disadvantage of the known devices for deburring welded workpieces, such as wires, strands or profiles, is that, when deburring welded burrs at the weld site, the workpieces and the deburring means may be damaged in the case of different geometric dimensions in the joining plane or in a plane substantially parallel thereto, for example in the case of different wire diameters or profile heights of the wires or profiles to be connected. This may thus be the case in particular when the deburring tool acts on burrs of the welding site from the side with the smaller wire diameter. Because the deburring openings are adjusted to the wire diameter during deburring. In the case of a deburring tool approaching the weld to be deburred from the side of the smaller wire diameter, the deburring opening is adjusted too small in relation to the wire with the larger diameter. This can lead to damage to the wire having a larger diameter and also to damage to the deburring tool itself, as a result of the pre-adjusted opening not being properly adjusted. Undesirable burr residues may also remain on the weld site.

In general, in the known device, burrs that are generated at the welded site are always removed from the right side at the time of joining. For this reason, the right clamping jaw of the device is movably designed in order to track the wire inserted on the right side of the device during welding. The clamping jaw with the wire on the left side is stationary. Since it is not possible for the operator of the device for inserting the wires to visually identify which of the wires may have a slightly larger or smaller wire diameter, it is often the case that the deburring tool acts from the side having the smaller wire diameter to the weld to be deburred. Thus, the previously described damage on the workpiece and on the tool results therefrom.

Starting from the disadvantages described above, the object underlying the invention is to provide a device and a method for butt welding which avoid these disadvantages.

Disclosure of Invention

The invention can be said to a butt welding device for butt welding workpieces, in particular wires, strands and profiles, in particular for double-resistance butt welding (Doppelstauch-Widerstandspressstumppfschwei βen), comprising a first clamping tool and a second clamping tool for receiving the ends of the workpieces to be joined, and at least one deburring tool for deburring the welded workpiece ends, wherein the at least one clamping tool is movable between an initial position and a welding position.

Each of these clamping tools is provided with a workpiece, for example a wire, to be clamped. The clamping tool can be moved relative to one another, for example by means of a drive, between a rest position and a welding position, so that the clamped workpiece ends can be moved relative to one another until they come into abutment. After the workpiece ends in the respective edge regions have been heated by the welding current, the clamping tools are moved relative to one another again, wherein the wire ends are connected and burrs are formed around the weld seam or the connection point. These burrs must be removed by means of a deburring tool.

According to the invention, at least one sensor is provided for determining the geometry, in particular the diameter, width or height, of the workpieces to be joined in the joining plane or in a plane substantially parallel thereto, wherein the control device controls the movement of the clamping tool and/or the movement of the deburring tool as a function of the geometry.

The clamping tool or the deburring tool can be actuated by means of the control device in such a way that the welded wire is deburred from the left or right side of the welding site, depending on the geometry. In particular, the wire should be deburred from the side with the larger geometry, in particular with the larger wire diameter. Thereby, damage to the wire and the deburring tool is largely avoided.

According to a first advantageous embodiment of the invention, the at least one sensor is configured as a travel measuring sensor. The distance between the object (for example, a clamping tool) and a reference position (for example, on a fixed point of the device) is measured by a distance measuring sensor. Additionally, the travel measurement sensor can be used for travel measurement for dimensional measurement for determining the height, thickness and width of the workpiece. Depending on the required range, the measurement can be performed by means of light or magnetic fields or acoustic waves or in direct contact with the workpiece. In this way, the geometry of the workpiece can be easily and accurately measured. In particular, from the measured dimensions, the geometry of the workpiece (for example the diameter of the wire) can be determined with sufficient accuracy and transmitted to the control device.

The sensor can be arranged on a receptacle for a clamping tool on the device, in particular laterally above a so-called claw holder.

In a further advantageous embodiment of the invention, the deburring means are each arranged on the clamping tool and can be moved together with the clamping tool. In this way, the deburring tool can be moved together with the clamping tool, so that no additional drive is required to move the deburring tool, in particular parallel to the workpiece.

It can thus be provided that the deburring tool can be moved in the direction of movement of the clamping tool as a function of the clamping tool. Alternatively, it is also conceivable for the deburring tool to be movable independently of the clamping tool in the direction of movement of the clamping tool. Thereby, a large degree of freedom is created for the movement of the deburring tool.

In particular, in order to additionally adjust the deburring tool, in particular a deburring blade arranged on the deburring tool, a further advantageous embodiment of the invention provides that the deburring tool is adjustably received on a holder, which is optionally connected to a clamping tool. In this way, if the deburring tool has wear, for example, it can be adjusted in a complementary manner, which wear would lead to the deburring tool no longer having sufficient properties for deburring, for example the blade sharpness of the deburring knife.

According to a further advantageous embodiment of the invention, each clamping tool has two axially adjustable clamping jaws, between which the workpiece can be clamped. The wire, in particular the ends of the wire, are each clamped between the clamping jaws and move together with the clamping tool, so that the clamped wire ends can abut and ultimately be welded to one another. In an advantageous manner, the clamping tool, in particular the clamping jaw, can also be used for current guidance, i.e. the current required for the welding process can be introduced into the workpieces to be joined by means of the clamping jaw.

For easier insertion of the workpieces into the apparatus, a stop for arranging and orienting at least one of the workpieces in the apparatus can be provided. In this regard, the first workpiece can first be inserted into the apparatus and oriented against the stop. In this way, the workpiece is then precisely positioned in the apparatus. The stop can then be removed, for example, retracted so that it is no longer in contact with the workpiece. Finally, a further workpiece to be joined can be inserted into the device, wherein the workpiece already inserted into the device can be used as a stop for the insertion and arrangement.

According to a separate concept of the invention, a method for butt welding, preferably double-press resistance butt welding, workpieces, in particular wires, strands and profiles, in particular by means of a butt welding device is characterized by the following steps:

a) The workpieces to be joined to each other are inserted into a butt welding apparatus,

B) The end of the workpiece to be joined is placed at the weld site,

C) Prior to butt welding, at least one geometric dimension, in particular the diameter, width or height, of the workpiece in the joining plane or in a plane substantially parallel thereto is determined,

D) Butt welding the end cross section of the end portions to be joined of the work pieces,

E) Upsetting the weld site of the butt-welded workpiece at an elevated temperature for causing a significant increase in cross-section,

F) Reducing the increased cross section to a predetermined end cross section of the workpiece by means of a deburring tool, and

G) At least one of the deburring means is actuated as a function of the geometry of the workpieces to be joined to one another.

According to a first advantageous embodiment of the method according to the invention, in the case of different geometries of the workpieces to be connected to one another, a deburring tool is used, which is associated with workpieces having a larger geometry. Furthermore, the deburring height or deburring opening is adjusted to this larger geometry, for example, a larger diameter of the wire. Thus, a deburring tool associated with a larger geometry is used, which has a correspondingly correctly adjusted deburring opening. In this way, damage to the deburring tool or the wire can be largely avoided.

For the case that there is no significant difference in the relevant geometry of the workpieces to be joined, the controller by default indicates, for example, always the right-hand one of the deburring tool for deburring. This is because this side is provided in the devices for deburring known from the prior art, i.e. known to the operator of the device.

Drawings

Other objects, advantages, features and application possibilities of the invention will emerge from the following description of embodiments with the aid of the drawing. All features described and/or illustrated herein form the subject matter of the present invention individually or in any meaningful combination, irrespective of how it is summarized in the claims or their returns.

Here, a part is schematically shown:

Figure 1 shows a butt welding apparatus with two clamping tools without the insertion of a workpiece,

Fig. 2 shows the apparatus according to fig. 1 with an inserted workpiece, wherein the workpiece with a relatively large diameter is located on the right side of the apparatus,

Fig. 3 shows the apparatus according to fig. 2, wherein a workpiece having a relatively large diameter is located on the left side of the apparatus,

Figure 4 shows the device according to figure 2 in a detailed view,

Fig. 5 shows method steps a) to j) for butt welding workpieces in a first arrangement, and

Fig. 6 shows method steps a) to j) for butt welding workpieces in a second arrangement.

The same or equivalent components are provided with reference numerals in the figures shown below in the figures, according to embodiments, for improving the readability.

Detailed Description

Fig. 1 shows a butt welding apparatus 10 without the manpowered workpieces 3, 4. The wires 3, 4 or wires are used, for example, as tools 3, 4 for carrying out the method according to the invention by means of the device 10 according to the invention according to fig. 2 to 6. These wires or wires are led out of the supply coil, for example, and are supplied to clamping jaws 15, 16, 17, 18 which are axially adjustable relative to each other hydraulically or pneumatically, of the first and second clamping tools 1,2 which can also be used for the supply of current.

To each of these clamping tools 1,2 with clamping jaws 15, 16, 17, 18, a wire 3,4, in particular a wire end or workpiece end 13, 14, is assigned, which is clamped by means of the clamping tools 1, 2. The clamping tools 1,2 can be moved relative to one another, for example by means of the drive 9, between a rest position and a welding position, so that the clamped wire ends 13, 14 can be moved horizontally relative to one another until the wire ends 13, 14 come into abutment. Of course, alternatively, in an embodiment not shown, it is provided that the clamping tools 1,2 are oriented such that they can be moved in the vertical direction.

The butt welding of the wire ends 13, 14 of the wires 3, 4 to be connected to one another, which were previously cut cleanly, takes place in a manner known per se (DE-OS 25 41 022) by means of the clamping jaws 15, 16, 17, 18. The welding burrs 21 produced during welding are also removed in a manner known per se (DE-OS 25 41 022) by the relative displacement of the clamping jaws 15, 16, 17, 18 and the deburring tool 5, 6 arranged thereon.

After butt welding, the connection or welding site 11 is upset at an elevated temperature, for example at least 450 ℃, for causing a cross-sectional expansion of, for example, at least 40% in total.

The welding current required for the welding process can be introduced into the wires 3,4 by means of clamping jaws 15, 16, 17, 18 arranged on the clamping tools 1, 2, respectively.

After heating the wire ends 13, 14 in the edge region by the welding current, the clamping tools 1,2 are moved relative to one another again, wherein the wire ends 13, 14 are connected and a welding burr 21 is formed around the weld seam or the connection point 11. The individual method steps are described in detail in fig. 5 and 6.

The deburring means 5, 6 are formed by tool holders 22 arranged on the clamping tools 1,2, respectively, with deburring blades 20 arranged thereon. In the present case, the deburring means 5, 6 are fastened to the clamping tools 1,2 by means of bolts. The tool holder 22 can be moved with the clamping tools 1,2 substantially parallel to the wire direction over the weld or connection point 11.

In the case of the deburring tool 5, 6 which is completely independent of the geometry of the workpiece 3, 4, but always moves on the weld joint 11 from one side only, as in the prior art, disadvantages are created which are addressed by the device according to the invention and the method according to the invention. Since at least one geometry of the workpieces 3, 4 to be joined in the joining plane or in a plane substantially parallel thereto is determined by the sensors 7, 8 before the deburring means 5, 6 start the deburring process by means of the control device 19.

In the present embodiment, the diameter of the wires 3, 4 to be joined is determined by means of the sensors 7, 8. However, it is also conceivable, in particular in the case of profile parts, to determine the width or height in the joining plane or in a plane substantially parallel thereto.

The sensors 7, 8 used can be a travel measuring system that measures the travel section in an electrical, optical or mechanical manner, for example by means of cable tension. It is also possible to consider the use of a travel sensor consisting of a glass rod provided with a row of very thin lines, which are optically scanned.

The geometry of the workpieces 3, 4 in the joining plane or in a plane substantially parallel thereto is determined by means of the sensors 7, 8. For example, the distance required for clamping the workpieces 3, 4 by the respectively assigned clamping jaws 15, 16, 17, 18 can be measured by means of the sensors 7, 8, so that the diameter of the respective wire 3, 4 can be determined from the data. The accuracy of this measurement can be about 1/10mm.

In the present case, the sensors 7,8 are arranged laterally and above the so-called claw, i.e. on the receiving section of the device 10 for clamping the tools 1,2, as shown in fig. 1 to 3.

In particular, in order to readjust the deburring tool 5, 6, for example a deburring blade 20 arranged on the deburring tool 5, 6, the deburring tool 5, 6 is adjustably received on a holder or tool carrier 22 which is optionally connected to the clamping tool 1, 2. In this way, if, for example, the deburring tool 5, 6 has wear which results in the characteristics required for deburring of the deburring tool 5, 6 (for example, the blade sharpness of the deburring tool 20) no longer being sufficient, the deburring tool 5, 6 can be readjusted.

The method steps for butt welding the workpieces 3, 4 are described below with the aid of fig. 5 and 6.

Fig. 5 a) to j) show the method steps for butt welding two wires 3,4, wherein in the present embodiment the wire 3 inserted into the device 10 at the left side 23 has a smaller diameter than the wire 4 inserted into the device at the right side 24.

Specifically, the butt welding of the leads 3, 4 of the present invention is performed by:

Fig. 5 a) shows the first wire 4 inserted into the device 10, b) fixes the wire 4 by means of the clamping jaws 15, 16 of the first clamping tool 1. The second wire is then inserted into the device 10 according to step c) and clamped in step d) by means of the clamping jaws 17, 18.

The welding process is then carried out in a manner known per se according to fig. 5 e). The welded areas are then released in steps e) to h), whereby a deburring process can take place.

After determining by means of the sensors 7, 8 that the wire 4 inserted on the right 24 in the present embodiment has a relatively large diameter compared to the other wire 2, the sensors 7, 8 transmit a corresponding signal to the control device 19. Subsequently, as shown by fig. 5 i), the clamping tool 2 assigned to the right side 24 of the device 10 (i.e. the side with the larger wire diameter) is moved in order to carry out the deburring process. Finally, the clamping tools 1, 2 release the welded wire (see fig. 5 h).

Butt welding is performed in a similar manner for the case where the wire 3 with a larger wire diameter is used for the left side 23 of the apparatus 10 instead of the right side 24. In this respect, the method steps of fig. 6 a) to f) correspond to the method steps of fig. 5 a) to f).

Deburring is then carried out according to FIGS. 6 f) to i). Since the wire 3 with the larger wire diameter is inserted on the left side 23 of the device 10, deburring takes place from the left side 23, as is shown by fig. 6 g) to i). Finally, in this embodiment, the welded wires 3, 4 are also released and can be removed, see fig. 6 j).

It may of course also happen that the wires 3,4 to be welded to each other have no or only small differences in their geometry, in particular in the wire diameter. In this case, deburring is always carried out from the right side 24 of the device. Of course, it is also possible to provide that the left side 23 is alternatively actuated according to a standard.

In the embodiment according to fig. 5 and 6, the first wire 4 is first inserted on the right side 24 of the device 10. However, in the sense of the present invention, it is also conceivable that the first wire 3, 4 is first inserted on the left side 23 of the device 10. In this case, the method steps according to fig. 5 and 6 will correspondingly proceed similarly.

List of reference numerals

1. First clamping tool

2. Second clamping tool

3. Workpiece

4. Workpiece

5. Deburring appliance

6. Deburring appliance

7. Sensor for detecting a position of a body

8. Sensor for detecting a position of a body

9. Driver(s)

10. Apparatus and method for controlling the operation of a device

11. Welding part

12. Stop piece

13. End of work piece

14. End of work piece

15. Clamping claw

16. Clamping claw

17. Clamping claw

18. Clamping claw

19. Control device

20. Deburring knife

21. Welding burr

22. Knife rest

23. Left side

24. Right side

Claims

1. A butt welding apparatus (10) for butt welding workpieces (3, 4), comprising a first clamping tool (1) and a second clamping tool (2) and at least one deburring tool (5, 6), the first clamping tool (1) and the second clamping tool (2) being adapted to receive ends (13, 14) of the workpieces (3, 4) to be joined, wherein the at least one clamping tool (1, 2) is movable between an initial position and a welding position, the at least one deburring tool (5, 6) being adapted to deburr the welded workpiece ends (13, 14),

It is characterized in that the method comprises the steps of,

At least one sensor (7, 8) is provided, the sensor (7, 8) being used to determine the geometry of the workpieces (3, 4) to be joined in the joining plane or in a plane substantially parallel thereto, and the sensor (7, 8) being arranged on a receptacle for a clamping tool (1, 2) on the device and laterally above the claw holder, wherein a control device (19) controls the movement of the clamping tool (1, 2) and/or of the deburring means (5, 6) as a function of the geometry such that deburring takes place from the side of the welding site having the larger geometry.

2. The device (10) according to claim 1, characterized in that the at least one sensor (7, 8) is configured as a travel measuring sensor.

3. The apparatus (10) according to claim 1 or 2, characterized in that a respective deburring tool (5, 6) is arranged on a clamping tool (1, 2) and is movable together with the clamping tool (1, 2).

4. A device (10) according to claim 3, characterized in that the deburring tool (5, 6) is movable according to the clamping tool (1, 2) in the direction of movement of the clamping tool (1, 2).

5. The apparatus (10) according to claim 1, characterized in that the deburring tool (5, 6) is adjustably received on a holder, which is connected with the clamping tool (1, 2).

6. The apparatus (10) according to one of claims 1, 2, 4, 5, characterized in that each clamping tool (1, 2) has two axially adjustable clamping jaws (15, 16, 17, 18), respectively, between which two clamping jaws (15, 16, 17, 18) the workpiece (3, 4) can be clamped.

7. The apparatus (10) of one of claims 1, 2, 4, 5, wherein the geometry is a diameter, a width or a height.

8. Method for butt welding of workpieces (3, 4) by means of a butt welding apparatus according to one of the preceding claims, characterized by the following steps:

a) The workpieces (3, 4) to be joined to one another are inserted into a butt welding device,

B) The ends (13, 14) of the workpieces (3, 4) to be joined are placed on a welding point (11),

C) Before butt welding, at least one geometry of the workpieces (3, 4) in the joining plane or in a plane substantially parallel thereto is determined,

D) Butt welding the end cross sections of the ends (13, 14) of the workpieces (3, 4) to be joined,

E) Upsetting said welding region (11) of the butt-welded workpieces (3, 4) at an elevated temperature for causing a significant increase in cross section,

F) Reducing the increased cross section to a predetermined end cross section of the workpiece (3, 4) by means of a deburring device (5, 6), and

G) At least one of the deburring means (5, 6) is actuated as a function of the geometry of the workpieces (3, 4) to be joined to one another.

9. Method according to claim 8, characterized in that the deburring tool (5, 6) is used in the case of different geometries of the workpieces (3, 4) to be connected to one another, the deburring tool (5, 6) being assigned to the workpiece (3, 4) having the larger geometry.

10. Method according to claim 8 or 9, characterized in that at least one clamping tool (1, 2) also has at least one deburring tool (5, 6).

11. Method according to claim 8 or 9, characterized in that at least one clamping tool (1, 2) is moved independently of the deburring tool (5, 6).

12. The method of claim 8 or 9, wherein the geometric dimension is a diameter, a width, or a height.